Effect of Si by Al on Phase-Transformation and Microstructure of MoSi2 based Compounds Synthesized by SHS Method

The aim of this study is investigation of phases and microstructure of synthesized products. DSC analysis proved that with addition of Al to Mo-Si system، the synthesis temperature is decreased from 1400 °C to 750 °C. The microstructural analysis by SEM showed homogeneous distribution of Al particles in microstructure so that with increasing the percentage of Al the grains growth and curvature of grain boundaries occur. XRD analysis confirmed that in X=0. 2 (Mo (Si1-x، Alx) 2) the major phase is Mo (Si، Al) 2 and in 0. 3≤X≤0. 5 the major phase transformers to Mo2. 85Al1. 91Si4. 81 as a new phase.